1. Field of the Invention
The present invention relates to a substrate processing apparatus, a substrate transfer device and a substrate transfer apparatus, particularly, to a semiconductor wafer processing apparatus, and more particularly, to a semiconductor wafer processing apparatus for processing a semiconductor wafer utilizing plasma such as a plasma etching apparatus, a plasma CVD (Chemical Vapor Deposition) apparatus and a plasma ashing apparatus, and to a substrate transfer device and a substrate transfer apparatus which can suitably be used for such a semiconductor wafer processing apparatus.
2. Description of the Related Art
FIG. 17 is a plan view showing an example of a plasma CVD apparatus 500 among conventional semiconductor wafer processing apparatuses using plasma.
Units, i.e., reaction chambers 552, 554, 556 and a cassette chamber 520 are provided around a load lock chamber 510 having a transfer robot 570 therein through gate valves 562, 564, 566 and 542, respectively. Each of the units is formed into a hermetic structure. The cassette chamber 520 is provided, apart from the gate valve 542, with an outer gate valve 544 for taking a cassette 530 in and out.
In the plasma CVD apparatus 500 having the above described structure, semiconductor wafers 5 are transferred between the cassette chamber 520 and the reaction processing chambers 552, 554, and 556 only by the transfer robot 570 of the load lock chamber 510. Therefore, it is difficult to enhance the processing efficiency of the semiconductor wafers 5. In order to increase the throughput, it is necessary to increase the number of corners or angles of the load lock chamber 510, that is to increase the number of sides of the load lock chamber 510, so as to increase the number of the reaction processing chambers 552, 554, and 556. However, with this method, substrate transfer by the transfer robot 570 more and more determines the entire processing speed of the substrate and thus, it is still difficult to enhance the processing efficiency of the semiconductor wafer 5.